Analysis of the Hydraulic Properties of Undisturbed Layered Loess in Northwest China

Qinghua Guo,Zhiqiang Zhao,Fuchu Dai

doi:10.3390/w11071379

Abstract

Extensive agricultural irrigation in the loess region of Northwest China has seriously damaged the local hydrogeological environment. To properly understand the hydrological processes and the hydraulic properties of the layered soil, the field soil column irrigation test, laboratory soil column infiltration test, and undisturbed soil sample hydraulic experiments were carried out. The results showed that the proposed infiltration model can continuously simulate the infiltration process of the loess–palaeosol sequence well. The layered structure may form a temporary groundwater table at the interface of the two different soils under irrigation conditions. This provides a scientific basis for proposing reasonable irrigation measures.

Highlights

The Chinese Loess Plateau, with widespread thick loess–palaeosol sequences, is largely a product of the Quaternary eolian activities
To prevent serious economic losses and casualties, many researchers have reasonably explored the mechanism of loess landslides, which is closely related to the variation in hydrological conditions from the perspective of constitutive relations [4,5,6]
Few studies have focused on the specific hydrologic processes and hydrogeological properties of the typical loess–palaeosol sequences under the irrigation condition, which has practical significance to guide seasonal agricultural irrigations

Summary

Introduction

The Chinese Loess Plateau, with widespread thick loess–palaeosol sequences, is largely a product of the Quaternary eolian activities. Many researchers have investigated the variation of the water content profile during the infiltration process of layered soil through indoor or field experiments [7,8]. Zohrab et al [9] showed that when the sublayer is more pervious than the top layer, the wetting front becomes unstable through the second layer. Li et al [10] investigated the effects of layered soil on wetting patterns and water distributions from a surface point source. They concluded that an interface existing in the layered soil, whether fine-over-coarse or coarse-over-fine, had a common feature of limiting downward water movement.

Methods

Results

Conclusion